Aircraft



' y 411939. Y AQR. LONG 2,164,414

AIRCRAFT I Filed Jan. 22, 1936 2 Sheets-Sheet 1 Alia/t R. Long, BY S rf/ 1'4 ATTORNEYS INVENTOR,

July 4, 1939. A ,-L 2,164,414

AIRCRAFT Filed Jm. 22, 1956 2 Sheets-Sheet 2 INVENTOR,

ATTORNEYS am 32% I meme M14. 1939 2,164,414"

UNITED STATES PATENT OFFICE AIRCRAFT Albert Regan Long, Elmhurst, N. Y. Application January 22, 1936, Serial No. 60,20! J Claims. (01. 244-132) This invention relates to the attachment of the or the edges of sheets together comprises a base covering to wings, fuselages, nacelles, control 2 which has formed therein a locking groove 3 surfaces, pontoons, boats and other elements of extending lengthwise thereof. In the particular aircraft and the attachment of inflatable rubberembodiment shown this groove is formed by the 5 like devices to aeroplane wingsfor preventing the side flanges 5 turned at an angle to the base 5 formatlon of ice, and similar applications. 2 and then turned inwardly towards each other The covering for aircraft elements, such as the to form inturned locking shoulders 4 remote from conventional fabric and metallic skins, is in conthe base 2, so that the outer part of the groove ventional practice attached by the conventional 3 is narrower than the inner part. The thin 16 sewing, rivetting and welding practices which are flexible sheet I is detachably locked into the not entirely satisfactory, because of the discongroove 3' by means of a special key or anchor tinuous nature of the attachment, roughness at strip 6 which is co-extensive in length with the joint, the high cost of assembly and the difliculty groove 3, in one piece or divided into sections. and expense in making repairs and replacements. This key 6 is arch shaped in cross section as shown These objections are obviated by the present inin Figs. 1 and 2 and the width of the arch is 15 vention, according to which the cover or covers slightly less than the opening leading into the are attached firmly and securely, whether fabric groove 3 past the shoulders 4. The key 6 is or metal, along continuous uninterrupted lines to formed of a material which permits it to be readthe framework and ina simple and easy manner, ily flattened out, such for example as of soft 2 requiring no particular skill and, moreover, in aluminum or other metals or alloys. The step of a manner which enables the cover or other deassembling the key is illustrated inFig. 2, wherevice to be quickly repaired or to be quickly rein it is observed that the key 6 is placed down moved and replaced. Moreover, as applied to airinto the groove 3 with the concave side toward craft, the only change from the conventional the base 2 and in engagement with the flexible structure is the formation of slightly modified. atsheet I, the latter being pushed into the groove 5 taching frame members which may be economiand into engagement with the base 2 of the frame cally manufactured and assembled without addimember, as indicated. The key or anchoring strip tional costs. 6 is then flattened out in any suitable manner to Other objects of the inventionwlll hereinafter occupy the position shown in Fig. 3, the side edges a thereof projecting underneath the locking shouli For a better understanding of the invention ders 4, and causing the sheet I to passaround reference may be had to the accompanying these edges and then inwardly around the locking drawings forming a part of this application shoulders 4, whereupon the thin sheet l is firmly wherein: anchored and locked to the member 2. It is Figs. 1 to 4 are diagrammatic views illustratlocked against pull or tension on the sheet in 35 ing the principle of the invention; any direction and particularly in the direction Fig. 5 is a diagrammatic sectional view showparallel to the flattened key member 6, as for ing the application of the invention to an aerofoil example as illustrated by the arrows in Fig. 3.

' surface; The flattening of the key element 6 may be ac- 40 Fig. 6 is adiagrammatic sectional view showing complished in any suitable manner, as for'ex- 40 the application of the invention to an aeroplane ample by the use of a convenient tool, preferably 3; having a flat bearing surface, which is inserted Figs. '1 to 10 are diagrammatic views illustratinto the groove 3 and caused to engage and ing specific covers and devices generally shown in traverse the length of the key. The key or an- Fig. 6; chor-strip 6 which is made of upsettable mate-. 45

- Fig. 11 is a sectionalview of a specific cap strip rial holds its flat form when thus flattened out 4 or'frame member to which the covering or skin and is preferably sufficiently soft and yieldable may be attached; and so as to enable the flattening of the same by Fig. 12 is a perspective view showing one methmanual pressure upon a suitable tool. The fabric v 0d of flattening out the fastening keys or anchor may be readily released from the frame member 50 strips. by inserting an instrument underneath the key Referring-to Figs. 1 to 3 of the drawings, the 6 and reupsetting and prying it out'of the groove. thin flexible sheet to-be attached to a frame mem- In Fig. 4 is illustrated the attachment of two ber is indicated at I. The frame member to which flexible sheets to each other in a continuous manthe sheet is to'be attached or for attaching sheets ner, along their edges. The two sheets thus fas- 55 tened together are indicated at I and 8 and at the same time these sheets are firmly fastened in the detachable manner described to the memher 2.

Fig. 5 shows the application of the invention to an aerofoil surface used in aircraft. The aerofoil ribs which give form to the surface are provided with cap strips having flanges I l and outer or supporting parts or bases 2 formed as indi cated in Figs. 1 to 3. These cap strips are adapted to receive the arch shaped key members 6, which are flattened out as described above to lock and fasten the aerofoil covering I which may be the conventional cloth aeroplane covering material, into the curved cap strips II to form a continuous line or double line of attachment throughout the width of the aerofoil and, moreover, in a deachable manner as above described. The ribs l may be of any conventional structure other than, the special cap strip structure above described. For example, two or more of the ribs Ill may be of any conventional watertight construction to form watertight compartments for aeroplane wings and this watertight character or seal is facilitated by the particular method of fastening the cover in the continuous manner shown.

Fig. 6 shows the application of the invention to an aerofoil, such for example as a lifting wing of an aeroplane, wherein" the nose of the wing is covered'by devices or covers of a different character or material from that of the covering of the rest of the wing. In this construction there is provided a pair of the special attaching members 2 extending lengthwise of the wing and adjacent the nose of the wing and fastened to the ribs Ill. The special covering or device for the nose is indicated at l2 and is attached tightly and firmly thereto by having its edges locked into the special members 2 by keys 6. This special nose covering may be a rubber boot to prevent the formation of ice on the wing or it may be of metallic skin. The remainder of the wing is covered by a suitable covering l3 which is detachably fastened to transverse ribs l0 similarly to the manner shown in Fig. 5.

Where 'the special nose covering is metal and the remainder of the wing covering is of the conventional cloth or fabric, I have shown in Figs. '7 to 10 inclusive the preferred method of fastening and anchoring the covers. The metallic strip I 2' is cut .to the desired width to reach from the upper member 2 to the lower member 2 when bent around the nose frame structure. Each edge of this strip is then formed with a bead or the like l which is inserted into the groove 3 in engagement with the nearest shoulder 4 of the groove, the edge l6 of the bead being bent to engage the base 2 of the attaching member. The beads I5 formed in the opposite edges of the sheet are forced past the shoulders 4 when the sheet is assembled in position and the offset of the beads is just suflicient to retain the sheet in the assembled position while assembling the key or anchor strip 6 and the cover l3. When the key member 6 is then inserted and flattened out, as shown in Figs. 9 and respectively, the edge of the key forces the bead l5 into the extremity of the groove, further upsetting the bead and forming a firm and secure look. In the particular embodiment shown in Figs. 8 to 10 a fabric l3 of conventional aeroplane cloth covering is also inserted around the nose, since it is more convenient in this case to have the covering l3 extend .uninterruptedly from the upper to the lower surface of the aeroplane. Fig. 8 illustrates the assembly of the metallic sheet with a bead IS in engagement with the shoulder 4 and the covering l3 placed thereover. Fig. 9 shows the key 8 dropped into the groove and the cloth [3' forced toward the base of the groove. Fig. 10 shows the key flattened out to firmly lock both the cloth I3 and the metallic skin I2 firmly in position. I have shown in Figs. 9 and 10 two keys within the groove, one key 6' underneath locking the metal and another key 6- above locking the cloth. The key 6 for the metal covering should be of harder material than the key 6, as for example of heat treated aluminum alloy. The keys 6 for the cloth may be and preferably are of soft aluminum.

The shape and size of the groove 3 may vary to suit different requirements but the general relative proportions shown give good results for conventional aeroplane coverings.

Fig. 11 shows the preferred form of cap strip in cross section. The cap strip here shown is of standard T section having the vertical 20 for fastening to the rib and the cross piece 2|. The latter has its ends turned at right angles to form the end parts 22 of the locking groove and these parts 22 in turn have their ends 23 turned inwardly in parallel relation with the cross 2|. The surfaces of the groove are all plane surfaces disposed at right angles to each other. The inwardly turned parts 23 are bevelled on their outer surfaces to have curvatures at the heels 24 of approximately 95 of an inch radius. This curved surface at the heel gradually merges into an arched surface inwardly towardthe plane of the vertical 20 which has a radius of approximately of an inch and this curvature is continued around to the points 26. I have found that'with curvatures of this character forming the bearing surface for textile fabric coverings for aeroplanes, the covering will not rupture under stress at the point of engagement with the anchoring member, but always on a. line removed therefrom and in some cases the rupturing line is approximately midway between the two lines of fastening. The placing of another layer of covering underneath the cover at the bearing surfaces 23 in some cases causes the rupturing line of the fabric to be shifted further away from the cap strip. The groove itself is deep enough to receive two of the keys 6 and a double layer of cloth and, accordingly, an aeroplane cloth covered wing may be very quickly and simply repaired by placing over the defective part a second sheet which is fastened to the cap strip by a second line of flattened out keys 6.

The dimensions of the cap strip shown in Fig. 11 and other figures may be proportioned to suit the particular requirements. For the conventional covering of aeroplane wings, the groove 3 in Fig. 11 may be approximately of an inch long and of an inch deep, with the thickness of the parts 2| and 22 roughly of an inch.

The key 6 may be of any desired, convenient and practicable length. I have found that keys of shorter length are handled and manipulated more easily than long keys. I have shown such shorter keys in Fig. 12 which are approximately I have also shown in Fig. 12 a sistanoe to upsetting operations locally applied to freely enter the opening between the shoulders I of the groove.

When. applying metallic skins to the aircraft wing or aerofoil, the skin is cut in sheets of the desired widths, as for example just wide enough to bridge two adjacent cap strips, and then beads are formed'as described above-in Fig. '7 for assembly upon the cap strips before the locking by assembling and flattening out the keys. When applying wing fabric coverings the latter may be put on in larger sheets, that is, the sheets may bridge any part of the .cap strips desired and the tension of the sheets may be regulated as desired as the sheets are fastened in position.

It is understood that while I have illustrated my invention as applied specifically to the aircraft art, it is understood that the principle is of wider application.

As above described, the keys 6 are made of soft thin readily upsettable metal or metal alloys and wherever that term is used in the claims it is understood to mean a key which can be flattened out by the application of hand pressure as shown in Fig, 12 and withouthammering and'which can be as readily upset and removed from the cap strip by the manual insertion of a suitable instrument underneath a flattened key. By the term thin flexible sheet or covering as used in the claims I mean a covering of the character used on conventional aerofoils.

1. In an aerofoil for aircraft, a supporting frame having cap strips with open undercut grooves formed thereon and a thin flexible sheetlike covering bound about said frame under tension, said grooves containing loops of the covering therein and thin flat locking keys, said covering being firmly fastened to said cap strip by said thin flat keys disposed in said grooves and locked therein in flat engagement with said loops formed from the covering, said keys being of a soft readily upsettable metal and having little resistance-to upsetting operations locally applied transversely of the surface thereof and ,which may be upset and removed from said grooves by the hand ap-' plication of a .tool underneath the same, but firmly resisting and holding fast against tensile stress exerted on the covering and each groove containing a multiplicity of short, juxtaposed,

flat, upsettable keys engaging the loop of the cover and locking the same therein.

2. In an aerofoil for aircraft, a supporting frame having cap strips with open undercut grooves formed thereon and a thin flexible sheetlike fabric covering bound about said frame under tension, said grooves containing loops of the covering therein and thin flat locking keys, said covering being flrmly fastened to said cap strips by said thin flat keys disposed in said grooves and locked therein in flat engagement with said loops formed from the covering, said keys being of a soft readily upsettable metal and having little retransversely of the surface thereof and which may be upset and removed from said grooves by the hand application of a tool underneath the same, but firmly resisting and holding fast against ten-v sile stress exerted on the covering, and which may be upset and removed from said grooves by the hand application of a tool underneath the same. 3. In an aerofoil for aircraft, a supporting frame having cap strips with open undercut grooves formed thereon and a thin flexible sheetlike covering bound about said frame under tension, said grooves containing loops of the covering therein and thin flat locking keys, said covering being jfirmly fastened to said cap stfips by said thin flat keys disposed in said grooves and locked therein in flat engagement with said loops formed from the covering, said keys being of a soft readily upsettable aluminum and having little resistance to upsetting operations locally appliedtransversely of the surface thereof and which may be upset and removed from said grooves by the hand application of a tool underneath the same, but firmly resisting and holding fast against tensile stress exerted on the. covering.

4. In an aerofoil for aircraft, a supporting frame having cap strips with open underclit grooves formed thereon and a thin flexible sheetlike covering bound about said frame under tension, said grooves containing loops of the covering therein and thin flat locking keys, said covering being flrmly fastened to said cap strips by said thin flat keys disposed in said grooves and locked therein in flat engagement with-said loops formed from the covering, said keys being of a soft readily upsettable aluminum alloy and having little resistanoe to upsetting operations locally applied transversely of the surface thereof and which may be upset and removed from said grooves by the hand application of a tool underneath the same, but firmly resisting and holding fast against tensile stress exerted on the covering. I

5. In anaerofoil for aircraft, a supporting frame having cap strips with open undercut grooves formed thereon and a thin flexible sheet- .like fabric covering bound about said frame under tension, said grooves containing loops of the covering therein and thin flat locking keys, said covering being firmly fastened to said cap strips by said thin flat keys disposed in said grooves and locked therein in flat engagement on the bottom and edges thereof with said loops, said keys being and of a soft readily upsettable metal and having little resistance to upsetting operations locally applied transversely of the surface thereof and 'of less thickness than the depth of the grooves fast against tensile stress exerted on the covering. co

' ALBERT a. LONG.

CERTIFICATE OF CORRECTION. I

V I July .14, 1939.

. ALBERT REGAN LONG. It is hereby certified that error appears in the p rinted. specification of the above mmbered patent requiring correction follows: Page 5, secand calm, lines 6 to8 inclusive, strike out the words and which may be wallet and removed from said grooves by the hand application of a tool underneath the-same" and" insert instead. said. grooves being formed of plane surfaces disposel'l at right angies to each other; andthat the said Letters Patent should be read with this correction therein that the same may'eonform to the record of the case in the Patent Office.

Signed and sealed this 22nd day or Atgust, A. D. 19.59;

Leslie Frazer (Seal) I Acting Commissioner of Patente. 

